XML 200 R172.htm IDEA: XBRL DOCUMENT
v3.20.4

Preferred Shares - Preferred Share Dividends Declared (Details) - CAD ($) $ in Millions |  | 12 Months Ended
--- | --- | ---
Mar. 01, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Series A |  |  |  |
Disclosure of classes of share capital [line items] |  |  |  |
Dividends declared |  | $ 9 | $ 5 | $ 9
Dividend rate on preference shares, spread | 2.03% |  |  |
Series B |  |  |  |
Disclosure of classes of share capital [line items] |  |  |  |
Dividends declared |  | $ 1 | 1 | 1
Dividend rate on preference shares, spread | 2.03% | 2.03% |  |
Series C |  |  |  |
Disclosure of classes of share capital [line items] |  |  |  |
Dividends declared |  | $ 14 | 8 | 14
Dividend rate on preference shares, spread |  | 3.10% |  |
Series E |  |  |  |
Disclosure of classes of share capital [line items] |  |  |  |
Dividends declared |  | $ 15 | 9 | 15
Dividend rate on preference shares, spread |  | 3.65% |  |
Series G |  |  |  |
Disclosure of classes of share capital [line items] |  |  |  |
Dividends declared |  | $ 10 | 7 | 11
Dividend rate on preference shares, spread |  | 3.80% |  |
Preferred Shares |  |  |  |
Disclosure of classes of share capital [line items] |  |  |  |
Dividends declared |  | $ 49 | $ 30 | $ 50

X
- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table. + References No definition available. + Details
Name: | ifrs-full_DisclosureOfClassesOfShareCapitalLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of dividends recognised as distributions to owners of the parent. [Refer: Parent [member]] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2019-01-01 -Paragraph 106 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_106_d&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_DividendsRecognisedAsDistributionsToOwnersOfParent
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Dividend Rate On Preference Shares, Spread + References No definition available. + Details
Name: | tac_DividendRateOnPreferenceSharesSpread
Namespace Prefix: | tac_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_ClassesOfShareCapitalAxis=tac_PreferenceSharesSeriesAMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfShareCapitalAxis=tac_PreferenceSharesSeriesBMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfShareCapitalAxis=tac_PreferenceSharesSeriesCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfShareCapitalAxis=tac_PreferenceSharesSeriesEMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfShareCapitalAxis=tac_PreferenceSharesSeriesGMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfShareCapitalAxis=ifrs-full_PreferenceSharesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |